Apparatus for reversing the bobbins in a braiding machine

ABSTRACT

An apparatus for reversing the position of the bobbin of braiding machines wherein each bobbin is rotatably coupled to a bobbin base which includes a bobbin locking mechanism for releasably coupling the bobbin base to the bobbin so that after the bobbin is accelerated in the direction of reversal caused by the tracking kinemetics, the locking mechanism is released during the counter-rotation of the bobbin base so that inertia of the bobbin rotator allow the causes it to rotate through the required angle relative to the bobbin base.

United States Patent 1191 Strangfeld 1 Feb. 6, 1973 1541 APPARATUS FOR REVERSING THE 1,693,121 11/1928 Robinson ..s7 51 ROBBINS [N A BRAIDING MACHINE 1,757,794 5/1930 Cook ..87/5l 1,826,545 10/1931 Higgins ..87/51 Inventor: Reiner Strangfeld, Bundesrepublic Deutschland, Germany Assignee: August Herzog Maschinenfabrik,

Bundesrepublic Deutschland, Germany.

[22] Filed: Feb. 10, 1971 [21] Appl. No.1 114,280

[30] Foreign Application Priority Data Feb. 10, 1971 Germany ..P 20 06 792.9

[52] US. Cl ..87/51, 87/38 [51] Int. Cl ..D04c 3/06 [58] Field of Search ..87/37, 78, 50, 51

[56] References Cited UNITED STATES PATENTS Pcgg ..87/38 Primary Examiner lohn Petrakes Attorney-Allison C. Collard [57] ABSTRACT An apparatus for reversing the position of the bobbin of braiding machines wherein each bobbin is rotatably coupled to a bobbin base which includes a bobbin locking mechanism for releasably coupling the bobbin base to the bobbin so that after the bobbin is accelerated in the direction of reversal caused by the tracking kinemetics, the locking mechanism is released during the counter-rotation of the bobbin base so that inertia of the bobbin rotator allow the causes it to rotate through the required angle relative to the bobbin base.

4 Claims, 2 Drawing Figures APPARATUS FOR REVERSING THE BOBBINS IN A BRAIDING MACHINE This invention relates to an apparatus for reversing the bobbins of a braiding machine. The machine has bobbins which are rotatable relative to their bases, in order to prevent the braided product from twisting due to the movement described by the bobbins.

With large, heavy ships cables and mooring ropes, which are currently produced from high tensible synthetic materials such as polypropylene, it is essential that the individual strands of the cable be braided without twisting; otherwise the yarns composing the strands would have varying initial stresses, with a consequent reduction of the tensile strength of the cable.

In order to prevent the material from twisting during the braiding process, it is necessary to arrange the path described by the bobbins through the driving elements in such a way that the 360 rotation of the bobbin base during its circuit is not also described by the bobbin itself. In other words, the path should be arranged so that the bobbins are almost uniformly orientated throughout their travel.

Conventional rope braiding machines are provided with a pinion rotatably mounted about a horizontal shaft attached to the bobbin at its lower end. This pinion engages the gear-teeth of a stationary plate which extends along the entire length of the bobbin tracks.

In another design of a braiding machine, the bobbin base and the bobbin itself (the rotating element) are mounted rotatably with respect to each other, and the material is prevented from twisting by the a reverse brake curve at each reversing section of the bobbin rotating element. In addition, an apparatus is already known which operates similarly to a planetary gear to prevent the material from twisting.

The designs incorporating gear systems are very costly to produce. The simpler form of construction embodying reverse braking curves has the disadvantage that the acceleration of the rotation of the bobbins (the rotating elements) through the reverse braking curve and the ensuing braking take place very abruptly on each occasion, since the reversal occurs on a relatively short section of the track. In addition to the increased noise thereby developed, increased motive power is required to effect the reversal.

It is an object of the invention to provide an apparatus which prevents the twisting of the braided material resulting from the movement described by the bobbins (the rotating elements), while avoiding the disadvantages of conventional methods.

The problem is solved according to the invention by locking the bobbin base with the bobbin during the acceleration in the reverse direction caused by the tracking kinematics, and releasing this coupling on completion of the acceleration, and leaving it released until the bobbin, owing to its inertia, has further rotated through the desired angle relative to the bobbin base during the subsequent counter-rotation of the latter. An advantage of this design is that considerably more time is available for the reversal of the bobbin than when reverse braking curves are used, since the latter must effect the angular acceleration and braking over a much shorter length of track. In other words, the braking of thereversing motion by means of the system covered by the present invention is gentler.

A four-element machine is used as a basis for explaining the idea of the invention. The apparatus will, of course, also operate with, for example, six-element machines in which the angle of reversal is smaller relative to the length of the reversing zone.

If, for example, a band brake is used as a coupling or bobbin-locking device, the release of the brake must take place precisely at the peak of the track curve of the wheels which guide the bobbin through the center of the machine, otherwise the full rotational moment will not be imparted to the bobbin.

If a brake or a locking mechanism and pawl is used, the brake may be released before the peak of the track curve which lies nearer to the center of the machine, since the bobbin is prevented by the pawl from rotating in the direction opposed to reverse-rotational direction. Thus, the brake lining can wear away without any danger that the brake will not have been fully released by the time the peak of the track curve is reached. The brake release occurs externally of the bobbin; that is, a releasing lever engages a control rail and disconnects the rotating bobbin from the base of the bobbin. While the bobbin base is executing its guided circuit along the track curve, the rotational moment initiated by the wheel guiding the bobbin through the center of the machine can operate on the bobbin. On completion of a predetermined rotational movement by the latter relative to the bobbin base, the bobbin-locking mechanism locks the bobbin and the bobbin base together, internally of the bobbin. The bobbin thus resumes the same direction of rotation as the bobbin base. i

An embodiment of the invention is shown diagrammatically in the drawings in order to clarify the braking and release operations and to illustrate additional features of the invention.

FIG. 1 is a track diagram of a four-element ropebraiding machine, and

FIG. 2 shows the locking arrangement between the bobbin base and the bobbin.

During movement on a guide track 1 in FIG. 1, the bobbin base 2 (which maintains its position relative to the guide track 1 owing to a guide shuttle which engages in the track) rotates clockwise through 360 during each complete circuit. In order to prevent the material braided from performing this torsional-movement, bobbin 3, located rotatably on base 2, must rotate backwards, counterclockwise, through an equivalent angle relative to the bobbin base. In the braiding wheel arrangement illustrated, this motion takes place in two stages, each of 180, the inertia of the bobbin being used to produce the reversing motion. The changes of motion during a 180 rotation will be explained with reference to FIG. 1.

Fig. 1 shows the position of the bobbin on the bobbin base in various positions during the cycle. It must, however, be stated that the bobbin position at point 7, following completion of a reverse rotation, is purely theoretical since, owing to frictional losses, the reversal of the bobbin on the base takes place somewhat later. However, this difference is not material to an understanding of the braking and release operations. In addition, a point is marked on the bobbin 3, in order that the reversing movements of this component may more readily be followed.

In addition to the translational movement along the track curve 1, alternating rotational motions are imparted to bobbin base 2. During its travel, it always rotates in the direction of the wheel driving it and changes its direction of rotation on transition to the adjoining driving wheel.

Thus, at track point of curve 1, bobbin base 2 and bobbin 3 coupled thereto rotate clockwise, in accordance with the direction of rotation of wheel 4a.

On the way to track point 6, bobbin base 2 and bobbin 3 coupled thereto change their direction of rotation to correspond to that of adjoining wheel 4b.

Before bobbin base 2 during its further travel is subjected to the change of rotation to the opposite direction, bobbin 3 is released from the base 2 by the action of the stationary control rail 8 on the releasing lever 9, so that an anticlockwise rotation in the reverse direction relative to the base is performed.

By adjustment of control rail 8, the timing of the release of the bobbin locking mechanism can be advanced within wide limits. Bobbin 3 and base 2 may even be released in the direction of reversal on the clockwise-rotating wheels 4a, 4c, since a twisting in a direction .opposite to the direction of reversal is prevented by a latch 11, a pawl or similar mechanism.

An example of an embodiment of a bobbin-locking mechanism 10 is shown in FIG. 2. Bobbin base 2 and bobbin 3 are shown in their locked position. The released positions of bobbin-locking mechanism 10 are shown in dashed line. The direction of reversal of bobbin 3 is marked with an arrow. Bobbin-locking mechanism 10 'is rotated into the position shown dashed by the impact of releasing lever 9 against control rail 8. Owing to the rotational moment the bobbin rotates in the direction of the arrow. Locking catch 13, urged by compression spring 12, holds the bobbinlocking mechanism 10 in the released position. On its rotation through 180, dog 14 strikes against catch 13, whereby compression spring 16 returns locking mechanism 10 to its locked position. After dog has engaged locking lever 9a, pawl 11 simultaneously locks bobbin-rotator 3 to base 2.

FIG. 2 should also be regarded merely as a diagrammatic arrangement, since 'in actually designing this component, a band brake would be used in order to ensure gentler braking. However, within the framework of the present application, it is not necessary to describe the design of already-known individual components such as shock absorbers, band brakes, and the like.

a bobbin, rotatably mounted on said bobbin base; locking means, for releasably locking said bobbin to said bobbin base so as to prevent rotational movement of said bobbin with respect to said bobbin base; and

means, mounted on the braiding machine adjacent said prescribed path, for engaging said locking means and thereby releasing said bobbin with respect to said bobbin base subsequent to rotation of said bobbins along said prescribed path by the rotating wheels so that said bobbin rotates in a direction opposite to the direction of rotation of said bobbin base by said rotating wheels through a predetermined angle of rotation.

2. The apparatus as recited in claim 1, wherein said locking means comprises a brake mounted on said bobbin base for engaging said bobbin and securing said bobbin from rotational movement with respect to said bobbin base.

3. The apparatus as recited in claim 2, wherein said brake is a band brake;

wherein said bobbin further comprises at least two abutment members, integrally formed therewith on the outside surface thereof and positioned opposite each other apart; and I wherein said bobbin base further comprises a pawl, pivotably mounted on said bobbin base, and biased by spring means so as to engage said bobbin and said abutment members and prevent rotation of said bobbin in a predetermined direction.

4. The apparatus as recited in claim 3, wherein said means for releasing said locking means comprises an elongated abutment rail member, mounted on the braiding machine adjacent said prescribed path, for engaging said locking means as it moves by said rail member and thereby releasing said bobbin with respect to said bobbin base. 

1. In a braiding machine, including a plurality of power driven rotatable wheels for moving a plurality of bobbins along a prescribed path, a bobbin including apparatus for reversing the position of the bobbins at selected points along said prescribed path, comprising: a bobbin base, moveable by the plurality of rotating wheels; a bobbin, rotatably mounted on said bobbin base; locking means, for releasably locking said bobbin to said bobbin base so as to prevent rotational movement of said bobbin with respect to said bobbin base; and means, mounted on the braiding machine adjacent said prescribed path, for engaging said locking means and thereby releasing said bobbin with respect to said bobbin base subsequent to rotation of said bobbins along said prescribed path by the rotating wheels so that said bobbin rotates in a direction opposite to the direction of rotation of said bobbin base by said rotating wheels through a predetermined angle of rotation.
 1. In a braiding machine, including a plurality of power driven rotatable wheels for moving a plurality of bobbins along a prescribed path, a bobbin including apparatus for reversing the position of the bobbins at selected points along said prescribed path, comprising: a bobbin base, moveable by the plurality of rotating wheels; a bobbin, rotatably mounted on said bobbin base; locking means, for releasably locking said bobbin to said bobbin base so as to prevent rotational movement of said bobbin with respect to said bobbin base; and means, mounted on the braiding machine adjacent said prescribed path, for engaging said locking means and thereby releasing said bobbin with respect to said bobbin base subsequent to rotation of said bobbins along said prescribed path by the rotating wheels so that said bobbin rotates in a direction opposite to the direction of rotation of said bobbin base by said rotating wheels through a predetermined angle of rotation.
 2. The apparatus as recited in claim 1, wherein said locking means comprises a brake mounted on said bobbin base for engaging said bobbin and securing said bobbin from rotational movement with respect to said bobbin base.
 3. The apparatus as recited in claim 2, wherein said brake is a band brake; wherein said bobbin further comprises at least two abutment members, integrally formed therewith on the outside surface thereof and positioned opposite each other 180* apart; and wherein said bobbin base further comprises a pawl, pivoTably mounted on said bobbin base, and biased by spring means so as to engage said bobbin and said abutment members and prevent rotation of said bobbin in a predetermined direction. 